1. Field of the Invention
Aspects of the present invention generally relate to an ophthalmologic apparatus.
2. Description of the Related Art
Various ophthalmologic apparatuses employing an optical device are used. Examples of an optical device for observing eyes include an anterior eye imaging device, a fundus camera, a scanning laser ophthalmoscope (SLO), and other various devices. Among these devices, an optical coherence tomography (OCT) imaging apparatus using optical coherence tomography utilizing multi-wavelength light wave interference can capture high-resolution tomographic images of a sample object. Hereinafter, the optical coherence tomography imaging apparatus will be referred to as an OCT apparatus. The OCT apparatuses are widely used in ophthalmologic diagnosis and the like to capture tomographic images of a retina in a fundus of a subject eye and also tomographic images of an anterior eye such as a cornea.
Meanwhile, it is known that a retina of a human eye includes plurality of layers. In ophthalmologic diagnosis, a doctor reads a layer structure and checks the state of a lesion area in a captured tomographic image. To check the state of a lesion area in a tomographic image of a retina, it is effective to display not only the tomographic image but also a layer thickness graph and a layer thickness map obtained by analyzing an image of a layer structure of the retina. It is also effective to detect an optic disc cup (Cup), an optic disc (Disc), and the like, and display measurement results such as sizes, ratios, and the like of the Cup, the Disc, and the like. It is also effective for checking a state of the lesion area to compare a calculated layer thickness, the sizes and ratios of the Cup, Disc, and the like with data of healthy eyes (international publication WO 2006/022045, Japanese Patent Application Laid-Open No. 2009-89792).
Statistical information in healthy eyes such as the thickness of each retinal layer, sizes, ratios, and distributions of the Cup, the Disc, and the like is stored in a normal database created for each race and each age-group from imaging data of healthy eyes (Japanese Patent Application Laid-Open No. 2013-153884).
In a case where imaging data of a patient is compared with statistical information stored in the normal database, the imaging data is compared with the statistical information in a race and an age-group that correspond to the race and age of the patient. An issue is how the imaging data of a patient should be compared with the statistical information stored in the normal database when a race or an age of the patient is outside a range of races or age-groups included in the statistical information.
International publication WO 2006/022045 and Japanese Patent Application Laid-Open Nos. 2009-89792 and 2013-153884 are silent about a method for the comparison of imaging data of a patient outside a range of races or age-groups included in statistical information stored in normal database.